Gap loss
Encyclopedia
Gap loss is a type of signal strength
Signal strength
In telecommunications, particularly in radio, signal strength refers to the magnitude of the electric field at a reference point that is a significant distance from the transmitting antenna. It may also be referred to as received signal level or field strength. Typically, it is expressed in...

 loss that occurs in fiber optic
Optical fiber
An optical fiber is a flexible, transparent fiber made of a pure glass not much wider than a human hair. It functions as a waveguide, or "light pipe", to transmit light between the two ends of the fiber. The field of applied science and engineering concerned with the design and application of...

 transmission when the signal is transferred from one section of fiber
Optical fiber
An optical fiber is a flexible, transparent fiber made of a pure glass not much wider than a human hair. It functions as a waveguide, or "light pipe", to transmit light between the two ends of the fiber. The field of applied science and engineering concerned with the design and application of...

 or cable to another.

The three basic types of gap loss are angular misalignment loss, lateral offset loss, and longitudinal displacement loss.
The losses tend to be proportional to the ratio of the core radius to the size of the gap or displacement. Formulas, examples and graphs can be found at Fiber Optic Communication - Couplers and Connectors
Gap loss can be reduced by filling the gap with a gel that matches the index of refraction of the fiber as closely as possible.

Definition

Specifically, gap loss happens when the signal from one end of a piece of cable is transferred to another, but there is a space, breakage, or gap between them. Since fiber optics transmit data via light the light can cross this gap, but spreads out and is weakened and diffused when it does so.

The light that crosses the gap and enters the next section of cable is broken up. Some of it reflects off, and some will hit the covering of the cable and not enter into the cable. If the gap is small, the gap loss will be small, but if the gap is very large, it may totally corrupt the signal.

Gap loss can be caused by many factors, but the most common is poorly fitted multi-sectional fiber optic cables. If there is a break in a directly buried
Direct-buried cable
Direct-buried cable is a kind of communications or transmissions cable which is especially designed to be buried under the ground without any kind of extra covering, sheathing, or piping to protect it.-Description:...

 fiber optic line then usually there will simply be a loss of signal.

Effects of gap loss

As a result of signal strength and cohesion being lost (due to the scattering of the light), a fiber optic signal suffering from gap loss is degraded in both quality and throughput.

See also

  • Optical fiber cable
    Optical fiber cable
    An optical fiber cable is a cable containing one or more optical fibers. The optical fiber elements are typically individually coated with plastic layers and contained in a protective tube suitable for the environment where the cable will be deployed....

     Color coding of connector boot and fiber cable jackets
  • Optical attenuator
    Optical attenuator
    An optical attenuator is a device used to reduce the power level of an optical signal, either in free space or in an optical fiber. The basic types of optical attenuators are fixed, step-wise variable, and continuously variable....

     Fiber optic attenuator
  • Optical fiber connector
    Optical fiber connector
    An optical fiber connector terminates the end of an optical fiber, and enables quicker connection and disconnection than splicing. The connectors mechanically couple and align the cores of fibers so that light can pass...

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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